Musannaf Ibn Abi Shayba 3:5664

Mu'tamir narrated to us, from Kathir ibn Nabata, who said: I heard Ibn Sirin say: I went out on a journey for Hajj or Umrah. When it was the last part of the night, I became in a state of major ritual impurity (janaba), and we did not have water with us, so I performed tayammum and prayed. When the forenoon (duha) arrived, a man said: "O Abu Bakr, did you repeat your prayer?" He said: "Even if I did not find water for twenty years, would I repeat my prayer?"